Clamp and guard for metal-shears



. P) HAYES.

CLAMP AND GUARD FOR METAL SHEARS.

APPLICATION FILED IAN. 11.1918.

1,330, 186. Patented Feb. 10,1920.-

sa@ 71%1, 5?' sa' C A TTORNEY UNITED STATES PATENT oEEroE.

BENJAMIN P. HAYES, or KANSAS CITY, MrSSoURI.

y CLAMP AND GUARD non METAL-SHEARS.

Specincation of Letters Patent. Patented Fell). `10, 1.9.20. I

ApplicationV led January 11, 1918. Seria1'No.'211,410.

To all whom it may concern.' Y v Be it known that I, BENJAMIN P. HAYES, a citizen of the United States, residing at Kansas City, in the county of Jackson and State of Missouri, have invented certainv new and useful Improvements in Clamps and Guards for Metal-Shears; and-I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in. the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to theletters and figures of reference marked thereon, which form a part of this specification.

My invention relates to improvements in metalshears and more particularly to an automatically operable clamping device for retaining a metal sheet rigidly at a set position during a shearing` operation; the principal lobject of the invention being to provide a clamping device of this character whereby a metal Sheet being sheared may be securely clamped during a cutting operation and which will be automatically moved, to release the Sheet, when the cutting is completed. Y

It is a further object of they invention to provide a device ofthis character that will serve as a guard to positively prevent any possible injury, which might be the result of accident or carelessness, to a workman operating themachine, and which moves auto# matically to and from clamping position under the control of a shear blade and requiresV no added or special mechanism for controlling its operation.

It is a still further' object of the invention toprovide such a guard that not only protects the operator of the machine. but also protects the machine by making it impossible to receive metal thicker than that which it is safe to cut therein;

In accomplishing these obiects I have provided improved details of structure the preferred forms of which are illustrated in the accompanying drawings. wherein Figure I is a perspective view of a crosscut metal shearing machinef equipped with a clamping' device constructed according to the present invention.

Fig. II is a transverse vertical section of the same Showing the clamping bar in functional position. A

Figl` III is an enlarged sectional vlew of a part ofthe machine showing the clamping bar raised. f Referring more in detail to the drawlngsz- 1 designates a power driven, cross-cut, metal shearing machine whereon a clamping device constructed according to the present invention is applied; the machine here shown comprisingthe flat working table 2 supported at its opposite ends by walls or frames 3-3 having flanged base portions 4 whereby the machine may be anchoredv to a floor or other supporting member and held solidly in operating position. f

Extending upwardly at opposite ends of the table are standards or frames 5-5, provided at their rear edges with vertical guideways 6 wherein the opposite ends of a. horizontal, blade supporting bar 7 are slidably contained the bar being adapted to move-vertically adiacent the rear edge of the table 2 and carrying a blade 8 having a cutting edge 9 adapted to move into or from coperative engagement with the cutting edge 10 of a similar, oppositelymounted blade 11 fixed to the rear edge of the table 2. Revolubly' mounted in the side frames 3 3 longitudnally beneath the table 2 is a driving shaft 12, one end of which carries a belt wheel 13 over which a driving belt 14 operates to drive the shaft, and at its opposite end is providedwith a gear wheel 15. adapted'totravel in mesh with a gear wheel 16 mounted on the end of a shaft 17 also revolubly mounted in frames 3 3 beneath the table and parallel with the shaft 12; the gear wheel 16 normallv revolves freely on the shaft 17 but may be locked thereto by the shifting of a clutch (not shown) that is actuated by the operation of a clutch Shifting` mechanism indicated at 18; the said shifting mechanism being actuated by the downward movement of a foot pedal 19 carried at the forward ends of paired -arms 20 fixed at their inner ends on a Shaft 21 mounted beneath the shaft 17 and revoluble under influence of the pedal to'actuate the clutch shifting mechanism.

rDisconnection of the Vclutch mechanism is` effected bv an upward movement of the foot pedal under the influence of tension springs 22 fixed at their opposite ends respectivelv to the arms 20 and' to brackets 23 extending from the inner faces of the wall 3`-3; the arrangement'being such thatswhen ,the pedal is in raised position the clutch mechanism.

is in disconnected relation with the vgear Wheel 16 but when .the pedal is depressed the sha-ft 2l is partially revolved to cause vthe gear 16 to belocked vtothe shaft 17 so that the latter will be'revolved to effect a cutting operation of the machine.

" The meansl provided for actuating the cut? ting blade 11 comprises a pair Vof eccentrics 25e-25 that arelfixed on the shaft 17 adjacent the inner faces of the side Walls 3-43 and which revolveV under influence of the shaft 17 v within collars 26'-26 mounted thereon. Extending upwardly from the col` of the blade 8 andl is rigidly heldin such a position by 'arms B14-31 extending forwardly from its opposite ends; the said arms being pivotally attached at their outer ends at av point about midway between the limits of the arc upon which the clamping device.

swings, by bolts or pins 32-32 to bearing members 33-433 fixed adj acentthe forward edge and at the ends ofthe table 2 so that the clamping bar may move toward or away from the tablel to effect a clamping engagement o r the releaselof a metal sheet that may be located on the table. l

Except at atime when acutting operation is taking place the cutting edge of the blade 8 is raised above the level of the table 2 that av sheet of metal 35 .maj7 be moved between the cutting edges of the blades. The clampf ing bar 30 is likewise raisedy and is held sufficiently from the table7 that it will not interfere Awith the placing of the metaljsheet, by means of studs 36 that project outwardly from the arms 28 at opposite sides of the machine and engage the under edges of the clamping bar and move downwardly 4with the blade to release the clamp bar so that it will take effect just before the lshearing operation. n y

It is apparent that the studs 36 may be so located that the risev of the bar 30'will be suflicient to receive stock not over a certain vthicknessjand all above the predetermined thickness will be rejected jtl iereby protecting the machine from' possible damage that might result fromcutting stock of a; greater thickness than that forv which the machine was designed." Y The'lampng of thev metal api-ate vbein-g site ends Vof the bar 30 and slidable atV their upper ends in guide bearings 39-39 formed at the upper ends of the side frames f; the said springs bearing at their upper endsagainst the guide bearings and at their lower ends: against nuts LlO--MY that are threaded on'the rods 38-38 so that the tension of the springs may be adjusted. Assuming that the device is so constructed and applied toa shearing machine as described, in using the machine the knife 8 is normally located abovethe level of the cutting` blade 11 andV tablet 2 so that aV 'metal sheet 35 may Vbe moved between the blades',l and the clamping bar 30 is retained' sufliciently above .the table. lov the lifting contact ofthe studs 36. that it will not interfere with a proper positioning of a sheet of metal below a certainthickness.

After the sheet of metal to be sheared is properly located, the operator of the machine presses'- downwardly on the foot pedal 19 which partially yrevolves the shaft 21 and actuates the clutch mechanism to lock the shaft 17 and gear wheel16 so that the shaft.

will be revolved andthe eccentrics 25-25 moved therebv to keffect a downward'movement of the blade'8 into shearing contact with the blade 11, to sever the sheet.

Itis apparent that as the lblade bar 7 moves downwardlv the clamping bar' 30 which is'supported against thepressure of the springs 37-37 Vbythe studs 36 is like:

wise lowered into clamping engagement with .the plate to be sheared; the studs being1 so clamped portion of the plate and the latter mav be'removed from or reset in thema# chine. j

It is apparent that with the` device'so ar-V ranged. an effective clamping means. isprovided andi that the vsam'e'operates automaticallv under the control of the shear bladewithout the addition of any special operating levers,and serves not only as a'clamping eratorj from accidental injury b v placinghis hand too far -with'inithe machine andk for' preventing the insertion of undesirable stock to the cutting blades. Y

device but also as a guard for saving an op;` f

v diii'erent strength, a desired clamping pressure may be obtained and by a proper location of the lifting studs 36 on the arms of the bar 7 the clamping bar 3Q may be raised at the proper time and a distance sufficient to permit placement of the metal sheet but not suflicient to permit injury t0 an operator.

Having thus described my invention what I claim as new therein and desire to secure by Letters-Patent is In 4a machine comprising a supporting table andV a movable blade for shearing metal plates, a clamping device pivotally mounted on the table, the pivot bein above the table about midway between the limits of the karc upon which the clamping device( swings, the clamping device being movable into and from clamping .position under the control of the blade to clamp the-plate to be sheared to the table duringl the shearing operation, the position of the pivot point insuring a clamping force upon the blade substantially at right angles to the table.

, In testimony whereof I aix my signature.

BENJAMIN P. HAYES. 

